You can use InternalsVisibleToAttribute to supply access to internal members of assembly A to members od asembly B.

//Inside Shared Assembly
[assembly:InternalsVisibleTo("Runtime")]

public class SharedClass
{
private string info;

public string Info
{
get
{
return info;
}
}

internal void SetInfo(string info)
{
this.info = info;
}
}

Manager defined by Runtime has access to SetInfo and calls it to modify info.